src/Pure/Isar/class_declaration.ML
author wenzelm
Wed Nov 09 21:44:06 2011 +0100 (2011-11-09)
changeset 45431 924c2f6dcd05
parent 45429 fd58cbf8cae3
child 45432 12cc89f1eb0c
permissions -rw-r--r--
misc tuning and simplification;
     1 (*  Title:      Pure/Isar/class_declaration.ML
     2     Author:     Florian Haftmann, TU Muenchen
     3 
     4 Declaring classes and subclass relations.
     5 *)
     6 
     7 signature CLASS_DECLARATION =
     8 sig
     9   val class: (local_theory -> local_theory) -> binding -> class list ->
    10     Element.context_i list -> theory -> string * local_theory
    11   val class_cmd: (local_theory -> local_theory) -> binding -> xstring list ->
    12     Element.context list -> theory -> string * local_theory
    13   val prove_subclass: (local_theory -> local_theory) -> tactic -> class ->
    14     local_theory -> local_theory
    15   val subclass: (local_theory -> local_theory) -> class -> local_theory -> Proof.state
    16   val subclass_cmd: (local_theory -> local_theory) -> xstring -> local_theory -> Proof.state
    17 end;
    18 
    19 structure Class_Declaration: CLASS_DECLARATION =
    20 struct
    21 
    22 (** class definitions **)
    23 
    24 local
    25 
    26 (* calculating class-related rules including canonical interpretation *)
    27 
    28 fun calculate thy class sups base_sort param_map assm_axiom =
    29   let
    30     val empty_ctxt = Proof_Context.init_global thy;
    31 
    32     (* instantiation of canonical interpretation *)
    33     val aT = TFree (Name.aT, base_sort);
    34     val param_map_const = (map o apsnd) Const param_map;
    35     val param_map_inst = (map o apsnd)
    36       (Const o apsnd (map_atyps (K aT))) param_map;
    37     val const_morph = Element.inst_morphism thy
    38       (Symtab.empty, Symtab.make param_map_inst);
    39     val typ_morph = Element.inst_morphism thy
    40       (Symtab.empty |> Symtab.update (Name.aT, TFree (Name.aT, [class])), Symtab.empty);
    41     val (([raw_props], [(_, raw_inst_morph)], export_morph), _) = empty_ctxt
    42       |> Expression.cert_goal_expression ([(class, (("", false),
    43            Expression.Named param_map_const))], []);
    44     val (props, inst_morph) =
    45       if null param_map
    46       then (raw_props |> map (Morphism.term typ_morph),
    47         raw_inst_morph $> typ_morph)
    48       else (raw_props, raw_inst_morph); (*FIXME proper handling in
    49         locale.ML / expression.ML would be desirable*)
    50 
    51     (* witness for canonical interpretation *)
    52     val prop = try the_single props;
    53     val wit = Option.map (fn prop =>
    54       let
    55         val sup_axioms = map_filter (fst o Class.rules thy) sups;
    56         val loc_intro_tac =
    57           (case Locale.intros_of thy class of
    58             (_, NONE) => all_tac
    59           | (_, SOME intro) => ALLGOALS (Tactic.rtac intro));
    60         val tac = loc_intro_tac
    61           THEN ALLGOALS (Proof_Context.fact_tac (sup_axioms @ the_list assm_axiom));
    62       in Element.prove_witness empty_ctxt prop tac end) prop;
    63     val axiom = Option.map Element.conclude_witness wit;
    64 
    65     (* canonical interpretation *)
    66     val base_morph = inst_morph
    67       $> Morphism.binding_morphism (Binding.prefix false (Class.class_prefix class))
    68       $> Element.satisfy_morphism (the_list wit);
    69     val eq_morph = Element.eq_morphism thy (Class.these_defs thy sups);
    70 
    71     (* assm_intro *)
    72     fun prove_assm_intro thm =
    73       let
    74         val ((_, [thm']), _) = Variable.import true [thm] empty_ctxt;
    75         val const_eq_morph =
    76           (case eq_morph of
    77              SOME eq_morph => const_morph $> eq_morph
    78           | NONE => const_morph);
    79         val thm'' = Morphism.thm const_eq_morph thm';
    80         val tac = ALLGOALS (Proof_Context.fact_tac [thm'']);
    81       in Skip_Proof.prove_global thy [] [] (Thm.prop_of thm'') (K tac) end;
    82     val assm_intro = Option.map prove_assm_intro
    83       (fst (Locale.intros_of thy class));
    84 
    85     (* of_class *)
    86     val of_class_prop_concl = Logic.mk_of_class (aT, class);
    87     val of_class_prop =
    88       (case prop of
    89         NONE => of_class_prop_concl
    90       | SOME prop => Logic.mk_implies (Morphism.term const_morph
    91           ((map_types o map_atyps) (K aT) prop), of_class_prop_concl));
    92     val sup_of_classes = map (snd o Class.rules thy) sups;
    93     val loc_axiom_intros = map Drule.export_without_context_open (Locale.axioms_of thy class);
    94     val axclass_intro = #intro (AxClass.get_info thy class);
    95     val base_sort_trivs = Thm.of_sort (Thm.ctyp_of thy aT, base_sort);
    96     val tac =
    97       REPEAT (SOMEGOAL
    98         (Tactic.match_tac (axclass_intro :: sup_of_classes @ loc_axiom_intros @ base_sort_trivs)
    99           ORELSE' Tactic.assume_tac));
   100     val of_class = Skip_Proof.prove_global thy [] [] of_class_prop (K tac);
   101 
   102   in (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) end;
   103 
   104 
   105 (* reading and processing class specifications *)
   106 
   107 fun prep_class_elems prep_decl thy sups raw_elems =
   108   let
   109 
   110     (* user space type system: only permits 'a type variable, improves towards 'a *)
   111     val algebra = Sign.classes_of thy;
   112     val inter_sort = curry (Sorts.inter_sort algebra);
   113     val proto_base_sort =
   114       if null sups then Sign.defaultS thy
   115       else fold inter_sort (map (Class.base_sort thy) sups) [];
   116     val base_constraints = (map o apsnd)
   117       (map_type_tfree (K (TVar ((Name.aT, 0), proto_base_sort))) o fst o snd)
   118         (Class.these_operations thy sups);
   119     val reject_bcd_etc = (map o map_atyps) (fn T as TFree (a, _) =>
   120           if a = Name.aT then T
   121           else error ("No type variable other than " ^ Name.aT ^ " allowed in class specification")
   122       | T => T);
   123     fun singleton_fixate Ts =
   124       let
   125         fun extract f = (fold o fold_atyps) f Ts [];
   126         val tfrees = extract (fn TFree (v, sort) => insert (op =) (v, sort) | _ => I);
   127         val inferred_sort = extract (fn TVar (_, sort) => inter_sort sort | _ => I);
   128         val fixate_sort =
   129           if null tfrees then inferred_sort
   130           else
   131             (case tfrees of
   132               [(_, a_sort)] =>
   133                 if Sorts.sort_le algebra (a_sort, inferred_sort) then
   134                   inter_sort a_sort inferred_sort
   135                 else
   136                   error ("Type inference imposes additional sort constraint " ^
   137                     Syntax.string_of_sort_global thy inferred_sort ^
   138                     " of type parameter " ^ Name.aT ^ " of sort " ^
   139                     Syntax.string_of_sort_global thy a_sort)
   140             | _ => error "Multiple type variables in class specification");
   141       in (map o map_atyps) (K (TFree (Name.aT, fixate_sort))) Ts end;
   142     fun after_infer_fixate Ts =
   143       let
   144         val S' =
   145           (fold o fold_atyps)
   146             (fn TVar (xi, S) => if Type_Infer.is_param xi then inter_sort S else I | _ => I) Ts [];
   147       in
   148         (map o map_atyps)
   149           (fn T as TVar (xi, _) =>
   150               if Type_Infer.is_param xi then Type_Infer.param 0 (Name.aT, S') else T
   151             | T => T) Ts
   152       end;
   153 
   154     (* preprocessing elements, retrieving base sort from type-checked elements *)
   155     val raw_supexpr =
   156       (map (fn sup => (sup, (("", false), Expression.Positional []))) sups, []);
   157     val init_class_body =
   158       fold (Proof_Context.add_const_constraint o apsnd SOME) base_constraints
   159       #> Class.redeclare_operations thy sups
   160       #> Context.proof_map (Syntax_Phases.typ_check 10 "reject_bcd_etc" (K reject_bcd_etc))
   161       #> Context.proof_map (Syntax_Phases.typ_check ~10 "singleton_fixate" (K singleton_fixate));
   162     val ((raw_supparams, _, raw_inferred_elems), _) =
   163       Proof_Context.init_global thy
   164       |> Context.proof_map (Syntax_Phases.typ_check 5 "after_infer_fixate" (K after_infer_fixate))
   165       |> prep_decl raw_supexpr init_class_body raw_elems;
   166     fun filter_element (Element.Fixes []) = NONE
   167       | filter_element (e as Element.Fixes _) = SOME e
   168       | filter_element (Element.Constrains []) = NONE
   169       | filter_element (e as Element.Constrains _) = SOME e
   170       | filter_element (Element.Assumes []) = NONE
   171       | filter_element (e as Element.Assumes _) = SOME e
   172       | filter_element (Element.Defines _) =
   173           error ("\"defines\" element not allowed in class specification.")
   174       | filter_element (Element.Notes _) =
   175           error ("\"notes\" element not allowed in class specification.");
   176     val inferred_elems = map_filter filter_element raw_inferred_elems;
   177     fun fold_element_types f (Element.Fixes fxs) = fold (fn (_, SOME T, _) => f T) fxs
   178       | fold_element_types f (Element.Constrains cnstrs) = fold (f o snd) cnstrs
   179       | fold_element_types f (Element.Assumes assms) = fold (fold (fn (t, ts) =>
   180           fold_types f t #> (fold o fold_types) f ts) o snd) assms;
   181     val base_sort =
   182       if null inferred_elems then proto_base_sort
   183       else
   184         (case (fold o fold_element_types) Term.add_tfreesT inferred_elems [] of
   185           [] => error "No type variable in class specification"
   186         | [(_, sort)] => sort
   187         | _ => error "Multiple type variables in class specification");
   188     val supparams = map (fn ((c, T), _) =>
   189       (c, map_atyps (K (TFree (Name.aT, base_sort))) T)) raw_supparams;
   190     val supparam_names = map fst supparams;
   191     fun mk_param ((c, _), _) = Free (c, (the o AList.lookup (op =) supparams) c);
   192     val supexpr = (map (fn sup => (sup, (("", false),
   193       Expression.Positional (map (SOME o mk_param) (Locale.params_of thy sup))))) sups,
   194         map (fn (c, T) => (Binding.name c, SOME T, NoSyn)) supparams);
   195 
   196   in (base_sort, supparam_names, supexpr, inferred_elems) end;
   197 
   198 val cert_class_elems = prep_class_elems Expression.cert_declaration;
   199 val read_class_elems = prep_class_elems Expression.cert_read_declaration;
   200 
   201 fun prep_class_spec prep_class prep_class_elems thy raw_supclasses raw_elems =
   202   let
   203 
   204     (* prepare import *)
   205     val inter_sort = curry (Sorts.inter_sort (Sign.classes_of thy));
   206     val sups = Sign.minimize_sort thy (map (prep_class thy) raw_supclasses);
   207     val _ =
   208       (case filter_out (Class.is_class thy) sups of
   209         [] => ()
   210       | no_classes => error ("No (proper) classes: " ^ commas_quote no_classes));
   211     val raw_supparams = (map o apsnd) (snd o snd) (Class.these_params thy sups);
   212     val raw_supparam_names = map fst raw_supparams;
   213     val _ =
   214       if has_duplicates (op =) raw_supparam_names then
   215         error ("Duplicate parameter(s) in superclasses: " ^
   216           (commas_quote (duplicates (op =) raw_supparam_names)))
   217       else ();
   218 
   219     (* infer types and base sort *)
   220     val (base_sort, supparam_names, supexpr, inferred_elems) = prep_class_elems thy sups raw_elems;
   221     val sup_sort = inter_sort base_sort sups;
   222 
   223     (* process elements as class specification *)
   224     val class_ctxt = Class.begin sups base_sort (Proof_Context.init_global thy);
   225     val ((_, _, syntax_elems), _) = class_ctxt
   226       |> Expression.cert_declaration supexpr I inferred_elems;
   227     fun check_vars e vs =
   228       if null vs then
   229         error ("No type variable in part of specification element " ^
   230           Pretty.string_of (Pretty.chunks (Element.pretty_ctxt class_ctxt e)))
   231       else ();
   232     fun check_element (e as Element.Fixes fxs) =
   233           List.app (fn (_, SOME T, _) => check_vars e (Term.add_tfreesT T [])) fxs
   234       | check_element (e as Element.Assumes assms) =
   235           List.app (fn (_, ts_pss) =>
   236             List.app (fn (t, _) => check_vars e (Term.add_tfrees t [])) ts_pss) assms
   237       | check_element _ = ();
   238     val _ = List.app check_element syntax_elems;
   239     fun fork_syn (Element.Fixes xs) =
   240           fold_map (fn (c, ty, syn) => cons (c, syn) #> pair (c, ty, NoSyn)) xs
   241           #>> Element.Fixes
   242       | fork_syn x = pair x;
   243     val (elems, global_syntax) = fold_map fork_syn syntax_elems [];
   244 
   245   in (((sups, supparam_names), (sup_sort, base_sort, supexpr)), (elems, global_syntax)) end;
   246 
   247 val cert_class_spec = prep_class_spec (K I) cert_class_elems;
   248 val read_class_spec = prep_class_spec Sign.intern_class read_class_elems;
   249 
   250 
   251 (* class establishment *)
   252 
   253 fun add_consts class base_sort sups supparam_names global_syntax thy =
   254   let
   255     (*FIXME simplify*)
   256     val supconsts = supparam_names
   257       |> AList.make (snd o the o AList.lookup (op =) (Class.these_params thy sups))
   258       |> (map o apsnd o apsnd o map_atyps o K o TFree) (Name.aT, [class]);
   259     val all_params = Locale.params_of thy class;
   260     val raw_params = (snd o chop (length supparam_names)) all_params;
   261     fun add_const ((raw_c, raw_ty), _) thy =
   262       let
   263         val b = Binding.name raw_c;
   264         val c = Sign.full_name thy b;
   265         val ty = map_atyps (K (TFree (Name.aT, base_sort))) raw_ty;
   266         val ty0 = Type.strip_sorts ty;
   267         val ty' = map_atyps (K (TFree (Name.aT, [class]))) ty0;
   268         val syn = (the_default NoSyn o AList.lookup Binding.eq_name global_syntax) b;
   269       in
   270         thy
   271         |> Sign.declare_const_global ((b, ty0), syn)
   272         |> snd
   273         |> pair ((Variable.check_name b, ty), (c, ty'))
   274       end;
   275   in
   276     thy
   277     |> Sign.add_path (Class.class_prefix class)
   278     |> fold_map add_const raw_params
   279     ||> Sign.restore_naming thy
   280     |-> (fn params => pair (supconsts @ (map o apfst) fst params, params))
   281   end;
   282 
   283 fun adjungate_axclass bname class base_sort sups supsort supparam_names global_syntax thy =
   284   let
   285     (*FIXME simplify*)
   286     fun globalize param_map = map_aterms
   287       (fn Free (v, ty) => Const ((fst o the o AList.lookup (op =) param_map) v, ty)
   288         | t => t);
   289     val raw_pred = Locale.intros_of thy class
   290       |> fst
   291       |> Option.map (Logic.unvarify_global o Logic.strip_imp_concl o Thm.prop_of);
   292     fun get_axiom thy =
   293       (case #axioms (AxClass.get_info thy class) of
   294          [] => NONE
   295       | [thm] => SOME thm);
   296   in
   297     thy
   298     |> add_consts class base_sort sups supparam_names global_syntax
   299     |-> (fn (param_map, params) => AxClass.define_class (bname, supsort)
   300           (map (fst o snd) params)
   301           [(Thm.empty_binding, Option.map (globalize param_map) raw_pred |> the_list)]
   302     #> snd
   303     #> `get_axiom
   304     #-> (fn assm_axiom => fold (Sign.add_const_constraint o apsnd SOME o snd) params
   305     #> pair (param_map, params, assm_axiom)))
   306   end;
   307 
   308 fun gen_class prep_class_spec before_exit b raw_supclasses raw_elems thy =
   309   let
   310     val class = Sign.full_name thy b;
   311     val (((sups, supparam_names), (supsort, base_sort, supexpr)), (elems, global_syntax)) =
   312       prep_class_spec thy raw_supclasses raw_elems;
   313   in
   314     thy
   315     |> Expression.add_locale I b (Binding.qualify true "class" b) supexpr elems
   316     |> snd |> Local_Theory.exit_global
   317     |> adjungate_axclass b class base_sort sups supsort supparam_names global_syntax
   318     ||> Theory.checkpoint
   319     |-> (fn (param_map, params, assm_axiom) =>
   320        `(fn thy => calculate thy class sups base_sort param_map assm_axiom)
   321     #-> (fn (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) =>
   322        Context.theory_map (Locale.add_registration (class, base_morph)
   323          (Option.map (rpair true) eq_morph) export_morph)
   324     #> Class.register class sups params base_sort base_morph export_morph axiom assm_intro of_class))
   325     |> Named_Target.init before_exit class
   326     |> pair class
   327   end;
   328 
   329 in
   330 
   331 val class = gen_class cert_class_spec;
   332 val class_cmd = gen_class read_class_spec;
   333 
   334 end; (*local*)
   335 
   336 
   337 
   338 (** subclass relations **)
   339 
   340 local
   341 
   342 fun gen_subclass prep_class do_proof before_exit raw_sup lthy =
   343   let
   344     val thy = Proof_Context.theory_of lthy;
   345     val proto_sup = prep_class thy raw_sup;
   346     val proto_sub =
   347       (case Named_Target.peek lthy of
   348          SOME {target, is_class = true, ...} => target
   349       | _ => error "Not in a class target");
   350     val (sub, sup) = AxClass.cert_classrel thy (proto_sub, proto_sup);
   351 
   352     val expr = ([(sup, (("", false), Expression.Positional []))], []);
   353     val (([props], deps, export), goal_ctxt) =
   354       Expression.cert_goal_expression expr lthy;
   355     val some_prop = try the_single props;
   356     val some_dep_morph = try the_single (map snd deps);
   357     fun after_qed some_wit =
   358       Proof_Context.background_theory (Class.register_subclass (sub, sup)
   359         some_dep_morph some_wit export)
   360       #> Proof_Context.theory_of #> Named_Target.init before_exit sub;
   361   in do_proof after_qed some_prop goal_ctxt end;
   362 
   363 fun user_proof after_qed some_prop =
   364   Element.witness_proof (after_qed o try the_single o the_single)
   365     [the_list some_prop];
   366 
   367 fun tactic_proof tac after_qed some_prop ctxt =
   368   after_qed (Option.map
   369     (fn prop => Element.prove_witness ctxt prop tac) some_prop) ctxt;
   370 
   371 in
   372 
   373 val subclass = gen_subclass (K I) user_proof;
   374 fun prove_subclass before_exit tac = gen_subclass (K I) (tactic_proof tac) before_exit;
   375 val subclass_cmd = gen_subclass (Proof_Context.read_class o Proof_Context.init_global) user_proof;
   376 
   377 end; (*local*)
   378 
   379 end;